Abstract:
The antioxidant activities of different fractions of
Mondia whiteii (Hook. f.) Skeels were measured by using three different assays (DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS(2,2'-azinobis-3-ethylbenzthiazoline-6-sulfonic acid) and FRAP (Ferric-Reducing Antioxidant Power), respectively). Total flavonoid and total phenol contents were also tested, and the chemical constituents of the dichloromethane fraction were further isolated and purified by AB-8 macroporous resin column chromatography (CC), Octadecylsilyl(ODSCC), Sephadex LH-20CC, and preparative-HPLC(High Performance Liquid Chromatography). Results showed that the dichloromethane fraction had the highest antioxidant activities and total phenol content. Furthermore, 10 compounds were obtained and identified, including 2-hydroxy-4-methoxybenzaldehyde(1), fraxetin(2), 7-metho-xycoumarin (3),
α-hydroxypropiosyringone (4),
ω-hydroxypropioguaiacone (5), cinnamic acid (6), salicylic acid (7), 4-methoxysalicylic acid (8), syringic acid (9), and azelaic acid (10). To the best of our knowledge, this study is the first to isolate compounds 3-10 from
Mondia whiteii.